BELLY FAT 101

There are three kinds of fat making your middle not so little: (1) Visceral fat hides around your organs, deep behind the ab muscles, and can't be grabbed. (2) Superficial subcutaneous fat bulges over your waistline and can be grabbed. (3) Deep subcutaneous fat is a combo of the two.

...BUT YOU CAN MELT IT

Dr. Abs, exercise physiologist Michele Olson, Ph.D., has the scientifically backed cardio how-to. Do this workout six times per week for the month to reveal a tight tummy.

First, log 10 minutes of cardio. Run, hop on a machine, whatever. Just keep your pace consistent. On a scale from 1 to 10, you're at a 7.

YOUR AB-NATOMY

You'll also have to train your entire core, made up of these four muscles: (1) rectus abdominis, which runs from your bra line to your pubic bone; (2) transverse abdominis, the deepest layer that wraps around your waist; (3) external obliques, close to the surface along your sides; and (4) internal obliques, underneath the external ones.

HOW TO TONE THE MUSCLES

Two routines were created by Dr. Abs to hit every inch of your core—all four ab muscles. Six days per week, choose either Workout I or Workout II, and do it before or after your cardio. Each takes 6 minutes, and you don't need equipment.

HOW YOU EAT MATTERS, TOO

Flat abs aren't just built in the gym—they're cooked up in the kitchen. For starters, you need to eat a sensible 1,600-calorie diet. But be strategic about where those calories come from. Certain foods can actually help regulate the hormones that tell our bodies where and how to store fat.

Think fiber and protein. Aim for at least 25 and 70 grams, respectively, each day. And timing matters. Eat every four to five hours so you're not ravenous. Staying satisfied can help keep stress levels in check, minimizing the production of cortisol, as too much of this hormone is linked to belly-fat storage. A high-protein, fiber-rich lunch suggestion: chicken salad with avocado on whole wheat with carrot sticks.

Carb up. In fact, get half of your calories from carbs. Unrefined "good" carbs provide a steady stream of energy that stabilizes insulin—a major factor in burning fat.

Tomatoes! Along with foods like yogurt and bananas, tomatoes are rich in potassium, known to combat bloat-inducing sodium.